This application claims the benefit of Korean Application No. P00-5452 filed Feb. 3, 2000, which is hereby incorporated by reference.
1. Field of the Invention
This invention relates to a liquid crystal display, and more particularly to a liquid crystal display panel and a method of fabricating the same. Although the present invention is suitable for a wide scope of applications, it is particularly suitable for easily controlling an alignment direction of liquid crystals as well as improving a viewing angle.
2. Description of the Related Art
Generally, an active matrix liquid crystal display (LCD) uses a thin film transistor (TFT) as a switching device to display a moving picture. The LCD can be manufactured smaller than a Brown tube. Thus, it has been widely used in various applications, such as a personal computer, a notebook computer, office automation equipment, and a portable electronic equipment, etc.
FIG. 1 is a perspective view showing a structure of the conventional liquid crystal display panel, and FIG. 2 is a cross-sectional view of the panel taken in the II-IIxe2x80x2 line direction in FIG. 1.
Initially referring to FIGS. 1 and 2, the conventional LCD panel includes upper and lower substrates 2 and 4 assembled to each other with a sealant, barrier ribs 8 for separating each liquid crystal cell 16, resin black matrices 10 formed on the lower substrate 4 if necessary, a pixel electrode 14 positioned on the lower substrate 4 at the center of the liquid crystal cell 16, a protrusion 12 positioned at the center of the pixel electrode 14, and a common electrode 6 formed on the upper substrate 2. A mixture of a liquid crystal and a photosensitive polymer is injected between the upper and lower substrates 2 and 4. A mask having a certain pattern is put on the upper substrate 2 where the mixture has been injected, and an ultraviolet (UV) ray is vertically irradiated thereon. At this time, the mixture at the portion exposed to the UV causes a phase separation between the liquid crystal and the polymer. When the phase separation occurs between the liquid crystal and the polymer, the polymer serves as the barrier ribs 8 to align liquid crystal molecules.
FIG. 3 is a plan view of the panel taken in the III-IIIxe2x80x2 line direction in FIG. 1. As shown in FIG. 3, liquid crystal molecules of the liquid crystal cell 16 have four sides and each side has the same size. The liquid crystal cell 16 is surrounded by the barrier ribs 8, which have a symmetrical alignment in all directions. When a voltage is applied to the common electrode 6 and the pixel electrode 14, the liquid crystal molecules aligned in this manner move into a symmetrical direction on all sides by electric fields. As a result, a viewing angle is improved. The protrusion 12 positioned on the pixel electrode 14 prevents an alignment disorder of the liquid crystal molecules that may be generated upon application of a data voltage. In other words, when a vertical alignment film is formed on the upper and lower substrates 2 and 4, the liquid crystal molecules having a negative dielectric anisotropy are vertically aligned. However, when a voltage is applied to the pixel electrode 14, the liquid crystal molecules aligned vertically at the center of the liquid crystal cell 16 may lose their balance. Thus, they may be laid down. In order to set up the laid-down liquid crystal molecules, the protrusion 12 serving as a center point is provided on the pixel electrode 14. The black matrices 10 are provided on the lower substrate 4 to align the liquid crystal molecules as well as to shield light.
However, the liquid crystal display panel having a structure as mentioned above has some drawbacks. For example, it is difficult to control an alignment direction of the liquid crystal molecules only with the polymer included in the barrier rib. Also, an ultraviolet ray should be irradiated on the liquid crystal display while applying a voltage to the display and heating the display at a high temperature in its fabrication process.
Accordingly, the present invention is directed to a liquid crystal display panel having a wide viewing angle and a method of fabricating the same that substantially obviate one or more of problems due to limitations and disadvantages of the related art.
Another object of the invention is to provide a liquid crystal display panel and a method of fabricating the same that easily control alignment directions of the liquid crystals as well as improve a viewing angle.
Additional features and advantages of the invention will be set forth in the description, which follows and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
To achieve these and other advantages and in accordance with the purpose of the present invention, as embodided and broadly described, a liquid crystal display panel includes first and second substrates, a first alignment layer on the first substrate, a second alignment layer on the second substrate, at least a pair of barrier ribs between the first and second alignment layers, wherein the barrier ribs are formed to have first and second angles with respect to the plane substantially perpendicular to the first and second substrates, and a liquid crystal layer between the first and second substrates.
In another aspect of the present invention, a method of fabricating a liquid crystal display panel having first and second substrates includes forming a first alignment layer on the first substrate, forming a second alignment layer on the second substrate, forming a liquid crystal layer between the first and second substrates, and forming at least one barrier rib between the first and second alignment layers, wherein the barrier ribs are formed to have first and second angles with respect to the plane substantially perpendicular to the first and second substrates.